scholarly journals Functioned catalysts with magnetic core applied in the ibuprofen degradation

2021 ◽  
Author(s):  
Giane Gonçalves Lenzi ◽  
Mylena Ferreira Lopes ◽  
Dana Isabelly Andrade ◽  
José Salvador Napoli ◽  
Andrieli Parolin ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Magnetic Separation ◽  
Reaction Medium ◽  
Solution Concentration ◽  
Magnetic Core ◽  
Organic Additive ◽  
Operation Conditions ◽  
The Matrix ◽  
Degradation Reaction ◽  
Activity Loss

Abstract In the present work, the performance of Ag/ZnO/CoFe2O4 magnetic photocatalysts in the photocatalytic degradation of Ibuprofen (IBP) was evaluated. This study considered the use of pure Ag/ZnO (5% Ag) and also use the Ag/ZnO/CoFe2O4 magnetic catalysts containing different amounts (5, 10 and 15% wt) of cobalt ferrite (CoFe2O4). The catalysts were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and photoacoustic Spectroscopy. To carried the photocatalytic degradation reaction, different concentrations of the ibuprofen contaminant solution (10, 20 and 30 ppm) and different concentrations of photocatalyst were tested (0.3 gL−1, 0.5 gL−1 and 1.0 gL−1). The reaction parameters studied were: IBP concentration, catalyst concentration, adsorption and photolysis, influence of the matrix, radiation source (solar and artificial) and the effect of organic additive. At the end of the photocatalytic tests, the best operation conditions were defined. Considering the obtained results of degradation efficiency and magnetic separation, the optimal parameters selected to proceed with the other tests of the study were: ibuprofen solution concentration 10 ppm, Ag/ZnO/CoFe2O4(5%) catalyst at a concentration of 0.3 g L−1 and pH 4.5 of the reaction medium. The results indicated the feasibility of magnetic separation of the synthesized catalysts. A long duration test indicated that the catalyst exhibits stability throughout the degradation reaction, as more than 80% of ibuprofen was degraded after 300 minutes. The photocatalytic activity was directly affected by the ferrite load. The higher the nominal load of ferrite, the lower the performance in ibuprofen degrading. It was also observed that the smallest amount of ferrite studied was enough for the catalyst to be recovered and reused. The adsorption and photolysis tests did not show significant results in the IBP degradation. In addition, it was possible to verify that the aqueous matrix, the use of solar radiation and the addition of additive (acid formic) interfered direct in the process. The catalyst reuse tests indicated that it can be recovered and reused at least three times without considerable catalytic activity loss.

Investigation of the effect of magnesium and activated carbon on the photocatalytic degradation reaction of ZnO photocatalyst

2021 ◽  
Vol 209 ◽  
pp. 212-218
Author(s):  
M. Sait Çevik ◽  
Ömer Şahin ◽  
Orhan Baytar ◽  
Sabit Horoz ◽  
Arzu Ekinci
Keyword(s):  
Activated Carbon ◽  
Photocatalytic Degradation ◽  
Degradation Reaction

scholarly journals Metal-Organic Framework MIL-101: Synthesis and Photocatalytic Degradation of Remazol Black B Dye

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Pham Dinh Du ◽  
Huynh Thi Minh Thanh ◽  
Thuy Chau To ◽  
Ho Sy Thang ◽  
Mai Xuan Tinh ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Photoelectron Spectroscopy ◽  
Metal Organic Framework ◽  
Nitrogen Adsorption ◽  
X Ray ◽  
Remazol Black B ◽  
Metal Organic ◽  
Degradation Reaction ◽  
Remazol Black ◽  
Organic Framework

In the present paper, the synthesis of metal-organic framework MIL-101 and its application in the photocatalytic degradation of Remazol Black B (RBB) dye have been demonstrated. The obtained samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption/desorption isotherms at 77 K. It was found that MIL-101 synthesized under optimal conditions exhibited high crystallinity and specific surface area (3360 m2·g-1). The obtained MIL-101 possessed high stability in water for 14 days and several solvents (benzene, ethanol, and water at boiling temperature). Its catalytic activities were evaluated by measuring the degradation of RBB in an aqueous solution under UV radiation. The findings show that MIL-101 was a heterogeneous photocatalyst in the degradation reaction of RBB. The mechanism of photocatalysis was considered to be achieved by the electron transfer from photoexcited organic ligands to metallic clusters in MIL-101. The kinetics of photocatalytic degradation reaction were analyzed by using the initial rate method and Langmuir-Hinshelwood model. The MIL-101 photocatalyst exhibited excellent catalytic recyclability and stability and can be a potential catalyst for the treatment of organic pollutants in aqueous solutions.

scholarly journals Photocatalytic degradation kinetics of Orange G dye over ZnO and Ag/ZnO thin film catalysts

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Derya Tekin ◽  
Taner Tekin ◽  
Hakan Kiziltas
Keyword(s):  
Thin Film ◽  
Kinetic Model ◽  
Photocatalytic Degradation ◽  
Degradation Kinetics ◽  
Reaction Medium ◽  
Rate Equations ◽  
Zno Thin Film ◽  
Model Studies ◽  
Thin Film Catalysts ◽  
Orange G

AbstractThe degradation of water pollutants with photocatalysts is one of the most studied subjects in the past 20 years. Although considerable studies have been completed in this field, kinetic model studies are still a major inadequacy. In this study, ZnO and Ag/ZnO thin film photocatalysts were synthesized and SEM-EDS, XRD and chronoamperometric measurements were used the characterization of photocatalysts. The network kinetic model was applied the photocatalytic degradation of Orange G using ZnO and Ag/ZnO thin film photocatalysts. The photocatalytic degradation of Orange G was investigated under the different reaction medium (initial dye concentrations, temperature, light intensity). It was found that the network kinetic model is the most appropriate model for the degradation of Orange G dye on the ZnO and Ag/ZnO thin film photocatalysts. The calculated adsorption equilibrium (KB) constant and activation energy of ZnO thin film photocatalyst are 0.0191 and 21.76 kj/mol, respectively. Additionally, the calculated values for Ag/ZnO thin film photocatalyst are 0.035 and 18.32 kj/mol. The general rate equations were determined for each photocatalysts.

Nanocrystal TiO2 Engulfed SiO2-Barium Hexaferrite for Enhanced Electrons Mobility and Solar Harvesting Potential

2015 ◽  
Vol 819 ◽  
pp. 226-231
Author(s):  
Azrina Abd Aziz ◽  
Shaliza Ibrahim ◽  
Saravanan Pichiah
Keyword(s):  
Phase Transformation ◽  
Photocatalytic Activity ◽  
Magnetic Separation ◽  
Sol Gel ◽  
Visible Region ◽  
Barium Hexaferrite ◽  
Band Gap Energy ◽  
Magnetic Core ◽  
Magnetic Photocatalyst ◽  
Titania Photocatalyst

Barium hexaferrite embedded-silica-titania photocatalyst (TiO2-SiO2-BaFe12O19) was synthesized through sol-gel, liquid catalytic phase transformation and solid reaction routes. The magnetic photocatalyst was aimed to harvest the photoenergy from the sunlight, minimize the electron-holes recombination rate, improve the long lifetime charge-carriers transfer to maximize the photocatalytic activity and enhances the separation and reusability of it. The as-synthesized photocatalyst was characterized and the photocatalytic activity was evaluated for the reduction of 2, 4-dichlorophenol (2, 4-DCP) under direct sunlight. The presence of SiO2 interlayer in TiO2-SiO2-BaFe12O19 prevents the phase transformation of magnetic core. TiO2-SiO2-BaFe12O19 benefits the magnetic separation with appreciable magnitude of coercivity (5035.6 Oe) and saturation magnetization (18.8256E-3 emu/g), respectively. The ferrite ions from the magnetic core which dispersed into TiO2 matrix exhibited an evident shift of the absorption in the visible region. This was again confirmed with the reduced band gap energy of 1.90 eV. Furthermore, TiO2-SiO2-BaFe12O19 destructed 100% of 2, 4-DCP compound within 150 min under very bright sunlight with an average irradiance of 820.8 W/m2 (results not shown). The embedding of BaFe12O19 with a SiO2 layer onto TiO2 nanocrystals contributed for an excellent solar-light utilization and ease magnetic separation of the nanosized photocatalyst.

Erucamide-Nanoclay Systems Obtained by Intercalation Process

2017 ◽  
Vol 899 ◽  
pp. 36-41 ◽  
Author(s):  
Josiane R. Silvano ◽  
J.M.M. Mello ◽  
Lucinao Luiz Silva ◽  
Humberto Gracher Riella ◽  
Márcio Antônio Fiori
Keyword(s):  
Differential Scanning Calorimetry ◽  
Reaction Medium ◽  
Film Surface ◽  
Polymeric Materials ◽  
Polymeric Films ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Intercalation Process ◽  
The Matrix

A major challenge in the manufacture of films for polymeric packaging is the definition and setting of the friction coefficient (FCO) for the film surfaces. The FCO values are established with the incorporation of additives during the processing of the polymeric films. But, the homogenization of these additives in the polymeric matrix is very difficult. The additives have different polarity that the matrix polymeric and not are mixable. So, these additives migrate for the surface of the polymeric films easily. Several molecules are used as sliding additives, but among the most efficient are the amides molecules, highlighting the erucamide. This molecule promotes the decrease of the FOC but due its quick migration for the polymeric film surface provides numerous problems for the manufacture of the polymeric packaging and during its application as the product. In this work a nanocomposite (MMT-ERU) was obtained by an intercalation process to improve the compatibility between the polymeric materials and the erucamide molecules. The results shown in this work refers to the studies about the intercalation processes of the erucamide molecules into nanoclays (montmorillonite) to obtain the nanocomposite MMT-ERU. The effect of the temperature and the percentage of the nanoclay in the intercalation processes were studied. The results of x-ray diffraction and differential scanning calorimetry shown that erucamide molecules were intercalated in the nanoclay structures and that intercalation efficiency depends positively of the temperature and percentage amount of the nanoclay in the reaction medium.

Speciation of Chromium via Laser-Induced Breakdown Spectroscopy of Ion Exchange Polymer Membranes

2005 ◽  
Vol 59 (2) ◽  
pp. 252-257 ◽  
Author(s):  
Christopher R. Dockery ◽  
Jack E. Pender ◽  
Scott R. Goode
Keyword(s):  
Cation Exchange ◽  
Natural Waters ◽  
Limit Of Detection ◽  
Polymer Membranes ◽  
Solution Concentration ◽  
Laser Induced Breakdown Spectroscopy ◽  
Breakdown Spectroscopy ◽  
Chromium Vi ◽  
Laser Induced Breakdown ◽  
The Matrix

A new method for the speciation of ng/mL concentrations of Cr(III) and Cr(VI) solutions with analysis by laser-induced breakdown spectroscopy (LIBS) is reported. Speciation is achieved by pre-concentration of the chromium onto commercially available cation exchange polymer membranes. Chromium(III) is removed directly by cation exchange; chromium(VI) in the filtrate is reduced to Cr(III) and concentrated onto a second cation exchange membrane, affording independent measurement of both species. Large volumes of waters containing Cr(III) and Cr(VI) can be concentrated onto the membranes and directly analyzed by laser-induced breakdown spectroscopy. The estimated limit of detection corresponds to 500 ng of Cr on the membrane: if a solution volume of 1 L is used, then the detection limit corresponds to a solution concentration of 0.5 ng/mL. Excellent separation of the chromium species is attained. Results show that overall method efficiencies range from 94–116% and are independent of the matrix. The influence of pH has been measured, and although Cr(VI) converts to Cr(III) in acidic solutions, the total Cr recoveries are not appreciably influenced by pH over the range of natural waters (4 to 9). In addition, speciation was performed in the presence of a number of different cations and showed that the method is robust in many different and complex matrices.

Study on the Photocatalytic Degradation of Diesel Pollutants over a Sol-Gel Prepared TiO2

2012 ◽  
Vol 476-478 ◽  
pp. 1926-1929
Author(s):  
Xiao Cai Yu ◽  
Dong Dong Hu ◽  
Qian Du ◽  
Xv Zheng ◽  
Ji Yao Guo
Keyword(s):  
Reaction Time ◽  
Photocatalytic Degradation ◽  
Room Temperature ◽  
Ph Value ◽  
Removal Rate ◽  
Sol Gel ◽  
Initial Concentration ◽  
Five Factors ◽  
Degradation Reaction ◽  
Diesel Degradation

Nanoscale titanium dioxide (TiO2) has been fabricated through a sound sol-gel method at room temperature with Tetra-n-butyl Titanate as the precursor, and the particles are characterized by XRD and TEM techniques. The results manifest that the as-prepared TiO2 is amorphous with the anatase structure and its size is around 33.2nm. Five factors, including dosage of TiO2, initial concentration of diesel, pH value, photocatalytic degradation reaction time and the presence of H2O2, are considered in the diesel degradation experiments. An orthogonal test is carried out to optimize the photocatalytic degradation of diesel pollutants based on the single-factor experiments. It reveals that when the dosage of TiO2 is 1.0g/L, the initial concentration of diesel is 0.5g/L, pH value is 6, the reaction time is 4h and the H2O2 dosage is 0.09%, the removal rate of diesel pollutants can up to 88%. Besides, the influence of each factor on removing diesel can be arranged in decreasing order: initial concentration of diesel> photocatalytic reaction time> pH value> TiO2 dosage> H2O2 dosage.

scholarly journals Direct photolysis and photocatalytic degradation of 2-amino-5-chloropyridine

2003 ◽  
Vol 68 (12) ◽  
pp. 961-970 ◽  
Author(s):  
Biljana Abramovic ◽  
Vesna Anderluh ◽  
Andjelka Topalov ◽  
Ferenc Gaal
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Uv Light ◽  
Parent Compound ◽  
Analytical Techniques ◽  
Direct Photolysis ◽  
Pyridine Moiety ◽  
Initial Substrate ◽  
Zero Order Reaction ◽  
Degradation Reaction

The direct photolysis and photocatalytic degradation of a pyridine pesticide analogue, 2-amino-5-chloropyridine, were investigated employing different analytical techniques ? potentiometry, for monitoring the pH and chloride genera- tion, spectrophotometry, for studying the degradation of the pyridine moiety, ion chromatography, for monitoring nitrate formation, and total organic carbon analysis for investigating the efficiency of the process. The photocatalytic degradation was studied in aqueous suspensions of titanium dioxide under illumination by UV light. It was found that chloride evolution was a zero-order reaction which takes place by direct photolysis, in that way differing from the degradation of the pyridine moiety, which takes place in the presence of titanium dioxide. Changes in pH during degradation indicate the formation of acidic intermediates and nitrate in addition to chloride. The effect of the initial substrate concentration was also investigated by monitoring the reaction of chloride generation as well as the degradation reaction of the pyridine moiety. It was found that degradation of the parent compound (2.5 mmol/dm3) by direct photolysis is completed in about 20 minutes, and of the pyridine moety by photocatalytic degradation in about nine hours. Based on the obtained data a possible reaction mechanism is proposed.

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